Head-restraining device for use in an MRI system and associated method

ABSTRACT

Apparatus and method for imaging a patient in an MRI system. This includes a frame, and at least one assembly that includes an earpiece positioner connected to a reference position on the frame, a first lockable joint on the positioner; and an earpiece connected to a patient-proximal end of the positioner by a second joint, wherein the first earpiece is movably positioned to a selected pitch angle, a selected yaw angle, and a selected one of a plurality of distances relative to the reference position on the frame. The first lockable joint is configured to be tightened to yieldably hold the first earpiece at the selected pitch and yaw angles, and at the selected one of the plurality of distances, relative to the reference position. Optionally a second substantially similar earpiece and assembly are provided. The earpiece(s) optionally include audio transducer(s) and/or RF coil(s).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/647,233 filed Jul. 11, 2017 by Brandon J. Tramm, titled “Apparatusand method for adjustable earpieces in an MRI system” (which issued asU.S. Pat. No. 9,901,286 on Feb. 27, 2018), which is a continuation ofU.S. patent application Ser. No. 14/538,635 filed Nov. 11, 2014 byBrandon J. Tramm, titled “Method and apparatus for adjustable earpiecesin an MRI system” (which issued as U.S. Pat. No. 9,700,232 on Jul. 11,2017), which claims priority benefit, under 35 U.S.C. § 119(e), of U.S.Provisional Patent Application No. 61/906,409 filed Nov. 19, 2013 byBrandon J. Tramm, titled “Method and apparatus for adjustable earpiecesin an MRI system,” each of which is incorporated herein by reference inits entirety.

FIELD OF THE INVENTION

This invention relates to the field of mechanical positioners and morespecifically to a method and apparatus for adjustable audio delivery ina magnetic-resonance-imaging (MRI) system that can be attached to a headcoil (in particular, in systems customized for pediatric imaging), inorder to position earpieces against the head of a patient for gentlyrestraining the patient's head to a single position and orientation(optionally including audio headphones for delivery of audio content;while in other embodiments, optionally including RF coils fortransmitting and/or receiving RF MRI information) and, in someembodiments, mechanisms for adjusting the position and characteristics(such as RF tuning and impedance matching of the RF coils attached tothe ear pieces) electrically and/or mechanically. In some embodiments, asubstantially similar unit to the earpiece is used to vary the positionof RF coils and then yieldably lock the coil in the desired position andorientation in RF-coil systems and units for other parts of the bodybesides the head.

BACKGROUND OF THE INVENTION

The problem: During MRI procedures, delivering audio has been cumbersomedue to sloppy headphone-to-patient interface provided by conventionalheadband-type earphones. This conventional device also introduces moreforeign objects into the imaging cavity and also increases the distancebetween the patient and the imaging surface. This reduces the efficiencyof the images and increases patient discomfort. These problems arefurther worsened when performing MRI scans on children. Childrentypically tend to move around more than adult subjects during scans.Therefore, it is important to deliver sound to occupy the child patientbeing scanned. It is important to have a large degree of adjustabilityto accommodate the various ranges of patient ear locations. Movement isalso an issue and it is important to restrain the patient's headmovements as much as possible without fully restricting an emergencyevacuation of the patient from the MRI system.

U.S. Pat. No. 8,854,042, titled “METHOD AND COILS FOR HUMAN WHOLE-BODYIMAGING AT 7 T,” filed 5 Aug. 2011 and issued 9 Feb. 2012 to John ThomasVaughan, Jr. and Charles A. Lemaire, is incorporated herein byreference. U.S. Pat. No. 8,854,042 describes MRI coils for humanwhole-body MR imaging. A progressive series of five new coils isdescribed. The first coil solves problems of transmit-field inefficiencyand inhomogeneity for heart and body imaging, with a close-fitting,16-channel TEM conformal array design with efficient shield-capacitancedecoupling. The second coil progresses directly from the first withautomatic tuning and matching, an innovation of huge importance formulti-channel transmit coils. The third coil combines the second,auto-tuned multichannel transmitter with a 32-channel receiver for besttransmit-efficiency, control, receive sensitivity and parallel-imagingperformance. The final two coils extend the innovative technology of thefirst three coils to multi-nuclear (³¹P-¹H) designs to make practicalhuman-cardiac imaging and spectroscopy possible for the first time at 7T.

U.S. Pat. No. 8,604,791, titled “ACTIVE TRANSMIT ELEMENTS FOR MRI COILSAND OTHER ANTENNA DEVICES,” filed 9 Sep. 2010 and issued 10 Dec. 2013 toJohn Thomas Vaughan, Jr and Charles A. Lemaire, is incorporated hereinby reference. This application describes apparatus and method thatinclude amplifiers for transceiver antenna elements, and morespecifically to power amplifying an RF (radio frequency) signal using adistributed power amplifier having electronic devices (such asfield-effect transistors) that are thermally and/or mechanicallyconnected to each one of a plurality of antenna elements (also calledcoil elements) to form a hybrid coil-amplifier (e.g., for use in amagnetic-resonance (MR) imaging or spectroscopy machine), and that isoptionally adjusted from a remote location, optionally includingremotely adjusting its gains, electrical resistances, inductances,and/or capacitances (which controls the magnitude, phase, frequency,spatial profile, and temporal profile of the RF signal)—and, in someembodiments, the components are compatible with, and function in, highfields (such as a magnetic field of up to and exceeding one tesla oreven ten tesla or more and/or an electric field of many thousands ofvolts per meter).

U.S. Patent Application Publication US 2012/0223709 titled “SIMULTANEOUSTX-RX FOR MRI SYSTEMS AND OTHER ANTENNA DEVICES,” of U.S. patentapplication Ser. No. 13/407,751 filed 28 Feb. 2012 by Scott M. Schillak,John Thomas Vaughan, Jr., Charles A. Lemaire and Matthew T. Waks, isincorporated herein by reference. This application describes anapparatus and a method that are more efficient and flexible, and obtainand connect high-power RF transmit signals (TX) to RF-coil devices in anMR machine or other devices and simultaneously receive signals (RX) andseparate net receive signals NRX) of interest by subtracting orfiltering to remove the subtractable portion of the transmit signal(STX) from the RX and preamplifying the NRX and signal processing thepreamplified NRX. In some embodiments, signal processing further removesartifacts of the transmitted signal, e.g., by digitizing the NRX signal,storing the digitized NRX signal in a memory, and performing digitalsignal processing. In some embodiments, the present invention alsoincludes pre-distorting the TX signals in order to be better able toidentify and/or remove the remaining artifacts of the transmitted signalfrom the NRX signal. This solution also applies to other high-powerRF-transmit-antennae signals.

U.S. patent application Ser. No. 13/831,752 titled “SNAP-ON COAXIALCABLE BALUN AND METHOD FOR TRAPPING RF CURRENT ON OUTSIDE SHIELD OF COAXAFTER INSTALLATION,” filed 15 Mar. 2013 by Matthew T. Waks, Scott M.Schillak and Charles A. Lemaire (which issued as U.S. Pat. No. 9,160,295on Oct. 13, 2015), is incorporated herein by reference. This applicationdescribes an apparatus and a method for a radially attachable RF trapattached from a side to a shielded RF cable. In some embodiments, the RFtrap creates a high impedance on the outer shield of the RF cable at afrequency of RF signals carried on at least one inner conductor of thecable. In some embodiments, an RF-trap apparatus for blocking straysignals on a shielded RF cable that has a peripheral shield conductorand a inner conductor for carrying RF signals includes: a case; an LCcircuit having a resonance frequency equal to RF signals carried on theinner conductor; projections that pierce and connect the LC circuit tothe shield conductor; and an attachment device that holds the case tothe cable with the LC circuit electrically connected to the shieldconductor of the shielded RF cable.

U.S. Pat. No. 8,299,681 issued to Snyder, et al. on Oct. 30, 2012,titled “Remotely adjustable reactive and resistive electrical elementsand method,” and is incorporated herein by reference. U.S. Pat. No.8,299,681 describes an apparatus and method that include providing avariable-parameter electrical component in a high-field environment andbased on an electrical signal, automatically moving a movable portion ofthe electrical component in relation to another portion of theelectrical component to vary at least one of its parameters. In someembodiments, the moving uses a mechanical movement device (e.g., alinear positioner, rotary motor, or pump). In some embodiments of themethod, the electrical component has a variable inductance, capacitance,and/or resistance. Some embodiments include using a computer thatcontrols the moving of the movable portion of the electrical componentin order to vary an electrical parameter of the electrical component.Some embodiments include using a feedback signal to provide feedbackcontrol in order to adjust and/or maintain the electrical parameter.Some embodiments include a non-magnetic positioner connected to anelectrical component configured to have its RLC parameters varied by thepositioner.

U.S. Pat. No. 5,449,206 to Lockwood issued Sep. 12, 1995 titled “Balland socket joint with internal stop” and is incorporated herein byreference. U.S. Pat. No. 6,042,155 to Lockwood issued Mar. 28, 2000titled “Ball and socket joint with internal stop” and is incorporatedherein by reference. These patents describe a first connector includesopposite ball and socket elements having a passageway formedtherethrough. The socket element has a cavity formed therein forreceiving a ball element of a second hose connector to form a hoseassembly. A ring is disposed within the cavity for limiting pivotalmovement of a ball element inserted therein to minimize the risk thatthe connectors, and thereby the hose assembly, will separate.

There is a long-felt need for a method and apparatus for adjustableaudio delivery and head restraint in an MRI system.

SUMMARY OF THE INVENTION

The present invention provides a solution: in some embodiments, a360-degree-plus adjustable cushioned head-restraining ear piecesintegrated into an MRI coil. In some embodiments, the MRI coil is apediatric head coil. In some other embodiments, the MRI coil is a headcoil for adults. In some embodiments, the adjustable cushionedhead-restraining ear pieces include an audio-delivery system integratedinto the MRI coil.

The adjustable cushioned audio system is designed to be used with a widearray of pre-existing audio headphones. In some embodiments, the designof the present invention includes of a series of ball-and-socketmechanisms that can be adjusted 360 degrees (in a combination of pitchand yaw relative to the longitudinal axis of the headphone-positioningrod) as well as in-and-out along the longitudinal axis of theheadphone-positioning rod, and rotation around the longitudinal axis ofthe headphone-positioning rod in a roll direction, and then tightened inthe proper position. In some embodiments, the earpieces are affixed tothe proximal end of the headphone-positioning rods using aball-and-socket joint that facilitates orienting the earpieces toconform to the sides of the patient's head. The system is modular indesign and can be integrated into other MRI coil housings with slightmodifications to those housings and/or the parts as described herein. Insome embodiments, the system is designed with standard tapered threadingon the ball-holding units. This allows an operator to apply increasedfriction between moving parts to firmly lock or snug them securely inplace by tightening the locking collars, while the friction can beovercome to release the patient in an emergency. The system also acts asa dual-purpose adjustable head-constraining and/or -restraining devicethat can be used with or without audio being supplied, in that thecushioned head pieces are implemented without audio generation in someembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan-view cross-sectional drawing of a head-coil system 192that uses two adjustable cushioned earpiece assemblies 101R and 101L,according to some embodiments of the present invention.

FIG. 2A is a plan-view cross-sectional drawing of two adjustablecushioned head-piece assemblies 101R and 101L, according to someembodiments of the present invention.

FIG. 2B is another plan-view cross-sectional drawing of two adjustablecushioned head-piece assemblies 101R and 101L, according to someembodiments of the present invention.

FIG. 3 is a perspective-view partially exploded drawing of a head-coilsystem 392 that uses two adjustable cushioned head-piece assemblies 101Rand 101L, according to some embodiments of the present invention.

FIG. 4 is a perspective-view partially exploded and partiallytransparent drawing of a head-coil system 392 that uses two adjustablecushioned head-piece assemblies 101R and 101L, according to someembodiments of the present invention.

FIG. 5 is an enlarged portion of a perspective-view partially explodedand partially transparent drawing of a head-coil system 192 that usestwo adjustable cushioned head-piece assemblies 101R and 101L, accordingto some embodiments of the present invention.

FIG. 6 is a perspective-view partially exploded and partiallytransparent drawing of a head-coil system 392 that uses two adjustablecushioned head-piece assemblies 101R and 101L, according to someembodiments of the present invention.

FIG. 7A is an exploded perspective-view drawing an adjustable cushionedhead-piece assembly 701, according to some embodiments of the presentinvention.

FIG. 7B is a plan-view cross-sectional of adjustable cushionedhead-piece assembly 701, according to some embodiments of the presentinvention.

FIG. 8A is a perspective-view drawing of a head-coil system 891 thatuses one adjustable cushioned head-piece assembly 701, according to someembodiments of the present invention.

FIG. 8B is a perspective-view drawing of a portion of head-coil system891 that uses one adjustable cushioned head-piece assembly 701,according to some embodiments of the present invention.

FIG. 9 is a perspective-view drawing of head-coil system 992 that usestwo adjustable cushioned head-piece assemblies 701, according to someembodiments of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Although the following detailed description contains many specifics forthe purpose of illustration, a person of ordinary skill in the art willappreciate that many variations and alterations to the following detailsare within the scope of the invention. Specific examples are used toillustrate particular embodiments; however, the invention described inthe claims is not intended to be limited to only these examples, butrather includes the full scope of the attached claims. Accordingly, thefollowing preferred embodiments of the invention are set forth withoutany loss of generality to, and without imposing limitations upon theclaimed invention. Further, in the following detailed description of thepreferred embodiments, reference is made to the accompanying drawingsthat form a part hereof, and in which are shown by way of illustrationspecific embodiments in which the invention may be practiced. It isunderstood that other embodiments may be utilized and structural changesmay be made without departing from the scope of the present invention.

The leading digit(s) of reference numbers appearing in the Figuresgenerally corresponds to the Figure number in which that component isfirst introduced, such that the same reference number is used throughoutto refer to an identical component which appears in multiple Figures.Signals and connections may be referred to by the same reference numberor label, and the actual meaning will be clear from its use in thecontext of the description.

As used herein, a non-magnetic mechanical-movement device is anyelectrically-controlled device (such as a linear positioner, rotarymotor, or pump) made of materials that do not move (or move to asubstantially negligible amount) due to a high magnetic field whensubjected to the high magnetic field. Such devices can be placed withinthe high magnetic field of a magnetic-resonance machine or thesuperconducting magnet of a particle accelerator without the danger ofthe device moving due to the magnetic field and/or without theundesirable result of changing the magnetic field due to their presence.In many of the descriptions herein, the term “motor” (such as motor 140)will be used as an example of such a non-magnetic mechanical movementdevice, however one of skill in the art will recognize that in otherembodiments, the “motor” can be implemented as a linear or rotary motordevice using suitable linkages, or as a pump that uses a liquid orpneumatic fluid to effectuate the described movement.

FIG. 1 is a plan-view cross-sectional drawing of a head-coil system 192that uses two adjustable cushioned earpiece assemblies 101R and 101L,according to some embodiments of the present invention. The presentinvention includes or is used with an MRI head coil 99. In someembodiments, head coil 99 is sized for pediatric-patient use, includinginfants, children or small adults. Such patients are often fearful,fidgety, and restless, and the earpiece assemblies (e.g., 101L and 101Rin FIG. 1, 701 in FIGS. 7A, 7B, 8A, 8B and 9) help to hold the patient'shead in a fixed location. In some embodiments, head coil 99 is of aconventional adult-head size. In some embodiments, the earpieceassemblies 101L, 101R, and/or 701 include audio transducers forproviding audio to the patient. In some other embodiments, the earpieceassemblies 101L, 101R, and/or 701 receive audio delivered throughplastic tubing connected to the earpiece, where the audio is from one ormore remote audio transducers.

In some embodiments, each of the assemblies 101R and 101L includes acushioned earpiece 110 and an earpiece-position-adjustment assembly 120.In some embodiments, each earpiece-position-adjustment assembly 120includes a tightenable ball-and-socket joint that includes ball unit123, and a tightenable socket assembly that includes a female-threadedsocket portion 124 and a male-threaded socket portion 125. In someembodiments, the male-threaded socket portion 125 is attached tohead-coil recess 126 (e.g., in some embodiments, using polymer screws,while in other embodiments, adhesives or other fastening means areused). Tightening female-threaded socket portion 124 to male-threadedsocket portion 125 releasably locks the pitch-and-yaw orientation ofball unit 123. By partially tightening female-threaded socket portion124 to male-threaded socket portion 125, a sufficient force applied fromthe head of the patient will overcome the friction lock and allow thepitch-and-yaw orientation to move, for example, for patient comfort oremergency extraction of the patient from the restraint. In someembodiments, ball unit 123 has a slotted male-thread portion that clampson rod 121 to restrain the in-and-out motion of rod 121 whenfemale-threaded nut 122 is tightened. In some embodiments, a furtherball-and-socket joint is provided at the end of the rod that is proximalto earpiece 110; for example, in some embodiments, by ball 111 andsocket 115. In some embodiments, each earpiece 110 includes an audiodelivery system that provides audio to the patient to calm and/orentertain the patient and/or communicate from the operator to thepatient. In other embodiments, each earpiece 110 is used to justrestrain head movement of the patient and omits the audio deliverysystem. In some embodiments, the pieces of earpiece-position-adjustmentassembly 120 are made of a polymer, such as for example, a polycarbonate(e.g., Lexan® or the like). In some embodiments, the tightenablefemale-threaded socket portion 124 and nut 122 are faceted (e.g., with astandard nut-faces in a hexagonal pattern), or have finger-tightenablewings (such as used in wing nuts) or the like.

FIG. 2A is a plan-view cross-sectional drawing of two adjustablecushioned earpiece assemblies 101R and 101L, according to someembodiments of the present invention. The various parts of cushionedearpiece assemblies 101R and 101L are described above in the discussionof FIG. 1.

FIG. 2B is another plan-view cross-sectional drawing of two adjustablecushioned head-piece assemblies 101R and 101L, according to someembodiments of the present invention. The various parts of cushionedearpiece assemblies 101R and 101L are described above in the discussionof FIG. 1.

FIG. 3 is a perspective-view partially exploded drawing of a head-coilsystem 392 that uses two adjustable cushioned head-piece assemblies 101Rand 101L, according to some embodiments of the present invention. Thevarious parts of cushioned earpiece assemblies 101R and 101L aredescribed above in the discussion of FIG. 1. Many of the various partsof cushioned earpiece assemblies 101R and 101L are described above inthe discussion of FIG. 1. Additionally, in contrast to head-coil system192, some embodiments of head-coil system 392 include a mirror 315 (fordelivering visual information to the patient) that is positionable andrepositionable to a variety of locations and orientation angles usingplastic flexible-piping units 314 that are stiff enough to hold mirror315 in the position fixed by an operator of the system. In someembodiments, flexible-piping units 314 include Loc-Line modular hosepieces such as are available from Lockwood Products, Lake Oswego, Oreg.(or described in U.S. Pat. Nos. 6,042,155 and 5,449,206, which areincorporated herein by reference). In some embodiments, the proximal endof rod 121 and its mating connector on earpiece 110 include Loc-Linemodular connector pieces such as are available from Lockwood Products,Lake Oswego, Oreg. (or described in U.S. Pat. Nos. 6,042,155 and5,449,206, which are incorporated herein by reference). In someembodiments, head coil 99 includes a top coil piece 344 which connectsto the other coil pieces 345, 346 and 347. In some embodiments, at asuitable location on coil face 91, a receptacle 126 is formed to receivethe base of male-threaded socket portion 125. In some embodiments, headcoil 99 includes a left-hand-side recess 348 and a right-hand-siderecess 349 that are sized to provide adequate clearance for earpieces110, in order that the earpieces 110 can be moved into proper positionagainst the ears of the patients as may be encountered in differentlocations due to different-sized heads. In some embodiments, rods 121are manually moved by the MRI operator to the desired/proper positions,and then the angle is fixed by tightening nut 124 and the depth to thepatient's ear is fixed by tightening nut 122. In some embodiments, thesetwo nuts provide a suitable amount of friction to hold rod in place upto a certain predetermined amount of applied force, but the frictionwill allow the angle and/or depth to be changed by an excess oradditional amount of force, in order to release the patient inemergencies. Head coil 99 includes a head rest surface 340 that supportsthe back of the patient's head.

FIG. 4 is a perspective-view partially exploded and partiallytransparent drawing of a head-coil system 192 that uses two adjustablecushioned head-piece assemblies 101R and 101L, according to someembodiments of the present invention. The various parts shown in FIG. 4are described above in the discussion of FIGS. 1-3.

FIG. 5 is an enlarged portion of a perspective-view partially explodedand partially transparent drawing of a head-coil system 192 that usestwo adjustable cushioned head-piece assemblies 101R and 101L, accordingto some embodiments of the present invention. The various parts shown inFIG. 5 are described above in the discussion of FIGS. 1-3.

FIG. 6 is a perspective-view partially exploded and partiallytransparent drawing of a head-coil system 192 that uses two adjustablecushioned head-piece assemblies 101R and 101L, according to someembodiments of the present invention. The various parts shown in FIG. 6are described above in the discussion of FIGS. 1-3.

FIG. 7A is an exploded perspective-view drawing an adjustable cushionedhead-piece assembly 701, according to some embodiments of the presentinvention. The various parts shown in FIGS. 7A and 7B are describedabove in the discussion of FIGS. 1-3.

FIG. 7B is a plan-view cross-sectional of adjustable cushionedhead-piece assembly 701, according to some embodiments of the presentinvention.

FIG. 8A is a perspective-view drawing of a head-coil system 891 thatuses a single adjustable cushioned head-piece assembly 701, according tosome embodiments of the present invention. The various parts shown inFIG. 8A and FIG. 8B are described above in the discussion of FIGS. 1-3and 7A-7B. In some embodiments, the single adjustable cushionedhead-piece assembly 701 holds only one side of the head of the patient,while the opposite side can be supported or cushioned in a conventionalmanner such as by using a pillow. This may be better suited for patientswith various types of head trauma or disease. In some embodiments, thehead-piece assembly 701 for the side opposite the single remainingassembly 701 is simply removed by loosening both nuts 122 and 124 (and,depending on the embodiment, by removing a rubber tip or otherattachment at the distal end of rod 121) and pulling the assembly 701toward the middle of head coil 891. (Note that in FIG. 8A, a cover hasbeen placed over receptacle 126 on the far side of the coil 891.)

FIG. 8B is another perspective-view drawing of a portion of head-coilsystem 891 that uses one adjustable cushioned head-piece assembly 701,according to some embodiments of the present invention.

FIG. 9 is a perspective-view drawing of head-coil system 992 that usestwo adjustable cushioned head-piece assemblies 701, according to someembodiments of the present invention. The various parts shown in FIG. 9are described above in the discussion of FIGS. 1-3 and 7A-7B. In someembodiments, head-coil system 992 omits the visual-stimulation assembly(e.g., mirror 315 of FIG. 3 is omitted).

In some embodiments, the system of the present invention includes a rodconnected to a head coil by a lockable ball joint, and an earpiececonnected to the rod by another ball joint.

In some embodiments, the one or more non-magnetic (e.g., piezoelectric)motors actuate control over electrical switches, amplitude modulators,frequency controllers, phase controllers, gain controllers, frequencymodulators and the like by using, for example, control of variableresistor(s), inductor(s), capacitor(s), antenna(s), dielectric shape(s),mechanical positioner(s) and the like.

In some embodiments, the system uses non-magnetic (e.g., piezoelectric)motors (or other mechanical-movement devices) that include linearactuators, rotary actuators, pumps (pneumatic (pressure or vacuum)and/or liquid pumps) and/or the like. In some embodiments, the systemoptionally includes non-magnetic sensors (e.g., using piezoelectric orother suitable technologies) that include linear strain gauges, rotarysensors, pressure or sound sensors (e.g., pneumatic (pressure or vacuum)and/or liquid), position sensors, light and image sensors, voltage orcurrent sensors, and/or the like. In some embodiments, such actuatorelements and/or sensor elements are used for remotely controlled roboticdiagnosis and examination, surgery, biopsy, and the like in a medicalenvironment (such as a magnetic-resonance machine).

In some embodiments, the present invention includes one or more of anyone or more of the devices in any of the figures herein in a combinedunit that connects the described variable components, optionallyincluding other conventional components.

Some embodiments further include an automatic parameter-adjustment unitoperatively coupled to the LC circuit and configured to adjustelectrical parameters of the LC circuit to control the resonancefrequency of the LC circuit.

Some embodiments further include an automatic parameter-adjustment unitthat has a non-magnetic mechanical actuator operatively coupled to theLC circuit and configured to adjust electrical parameters of the LCcircuit to control the resonance frequency of the LC circuit.

In some embodiments, the plurality of projections electrically connectedto the LC circuit include a first plurality of pointed projections at afirst end of the case and a second plurality of pointed projections at asecond end of the case opposite the first.

In some embodiments, the plurality of projections electrically connectedto the LC circuit include a first plurality of pointed projections at afirst end of the case and a second plurality of pointed projections at asecond end of the case opposite the first, wherein each one of the firstplurality of pointed projections is capacitively coupled to acylindrical conductor spaced apart from the shield conductor of theshielded RF cable, and wherein each one of the second plurality ofpointed projections is capacitively coupled to the cylindricalconductor.

In some embodiments, the plurality of projections electrically connectedto the LC circuit include a first plurality of pointed projections onlyat a first end of the case and no pointed projections at a second end ofthe case opposite the first, and the LC circuit includes a conductivecylinder that is electrically connected to first plurality of pointedprojections only at a first end of the case.

In some embodiments, the LC circuit includes a plurality of pi networksarranged at different radial directions around the shielded RF cable.

In some embodiments, the LC circuit includes a plurality of Tee networksarranged at different radial directions around the shielded RF cable.

In some embodiments, the LC circuit includes a plurality of quad-couplernetworks arranged at different radial directions around the shielded RFcable.

In some embodiments, the LC circuit includes a plurality of Wilkensonpower-splitter-combiner networks arranged at different radial directionsaround the shielded RF cable.

In some embodiments, the LC circuit includes a plurality ofrat-race-coupler networks arranged at different radial directions aroundthe shielded RF cable.

In some embodiments, the present invention provides a method thatincludes: providing a case having an LC circuit that is mounted to thecase and that has a resonance frequency at a frequency of RF signalscarried on the at least one inner conductor; a piercing structureelectrically connected to the LC circuit and configured to pierce andelectrically connect the LC circuit to the shield conductor of theshielded RF cable; and an attachment device configured to hold the caseto the shielded RF cable with the LC circuit electrically connected tothe shield conductor of the shielded RF cable.

Some embodiments further include automatically adjusting electricalparameters of the LC circuit to adjust the resonance frequency.

Some embodiments further include automatically adjusting electricalparameters of the LC circuit to adjust the resonance frequency by movinga non-magnetic mechanical-movement device.

In some embodiments of the method, the plurality of projectionselectrically connected to the LC circuit include a first plurality ofpointed projections at a first end of the case and a second plurality ofpointed projections at a second end of the case opposite the first.

In some embodiments of the method, the plurality of projectionselectrically connected to the LC circuit include a first plurality ofpointed projections at a first end of the case and a second plurality ofpointed projections at a second end of the case opposite the first,wherein each one of the first plurality of pointed projections iscapacitively coupled to a cylindrical conductor spaced apart from theshield conductor of the shielded RF cable, and wherein each one of thesecond plurality of pointed projections is capacitively coupled to thecylindrical conductor.

In some embodiments of the method, the plurality of projectionselectrically connected to the LC circuit include a first plurality ofpointed projections only at a first end of the case and no pointedprojections at a second end of the case opposite the first, and the LCcircuit includes a conductive cylinder that is electrically connected tofirst plurality of pointed projections only at a first end of the case.

In some embodiments of the method, the LC circuit includes a pluralityof pi networks arranged at different radial directions around theshielded RF cable.

In some embodiments, the LC circuit includes a plurality of Tee networksarranged at different radial directions around the shielded RF cable.

In some embodiments of the method, the LC circuit includes a pluralityof quad-coupler networks arranged at different radial directions aroundthe shielded RF cable.

In some embodiments of the method, the LC circuit includes a pluralityof Wilkenson power-splitter-combiner networks arranged at differentradial directions around the shielded RF cable.

In some embodiments of the method, the LC circuit includes a pluralityof rat-race-coupler networks arranged at different radial directionsaround the shielded RF cable.

In some embodiments, the present invention provides a radiallyattachable RF trap attached from a side to a shielded RF cable. In someembodiments, the RF trap creates a high impedance on the outer shield ofthe RF cable at a frequency of RF signals carried on at least one innerconductor of the cable. In some embodiments, an RF-trap apparatus forblocking stray signals on a shielded RF cable that has a peripheralshield conductor and a inner conductor for carrying RF signals includes:a case; an LC circuit having a resonance frequency equal to RF signalscarried on the inner conductor; projections that pierce and connect theLC circuit to the shield conductor; and an attachment device that holdsthe case to the cable with the LC circuit electrically connected to theshield conductor of the shielded RF cable.

In some embodiments, the present invention provides a non-transitorycomputer-readable medium having instructions stored thereon for causinga suitably programmed information processor to execute a method thatcomprises: autocontrolling an electrical parameter of an LC circuit thatis mounted to a case of a snap-on balun attached to a shielded RF cablethat has a peripheral shield conductor and at least one inner conductorfor carrying RF signals, wherein the LC circuit has a resonancefrequency at a frequency of RF signals carried on the at least one innerconductor, wherein the case includes a piercing structure electricallyconnected to the LC circuit and configured to pierce and electricallyconnect the LC circuit to the shield conductor of the shielded RF cable.

In some embodiments of the computer-readable medium, the method furtherincludes using a feedback signal operatively coupled to the programmableinformation-processing device to provide feedback control in order tomaintain the electrical parameter of the LC circuit.

In some embodiments of the computer-readable medium, the method furtherincludes controlling resistance, inductance and capacitance (RLC) valuesof the LC circuit.

In some embodiments, the present invention provides an apparatus forholding a patient in a magnetic-resonance imager (MRI) system. Thisapparatus includes: a first MRI-compatible earpiece assembly, the firstearpiece assembly including a rod connected to a head coil by a firstlockable ball joint and an earpiece connected to a proximal end of therod by a second ball joint, wherein the rod is movably positioned to aselected one of a plurality of possible pitch and yaw angle combinationsof the rod relative to the head coil and to a selected one of aplurality of insertion depths relative to the head coil, and then thefirst ball joint is configured to be tightened to yieldably hold the rodat the selected pitch angle, yaw angle and insertion depth.

In some embodiments, the apparatus further includes: the head coil; anda second MRI-compatible earpiece assembly, wherein the secondMRI-compatible earpiece assembly is substantially similar to the firstMRI-compatible earpiece assembly but mirror-symmetric to the firstMRI-compatible earpiece assembly about a central plane of the head coil,and wherein the first and the second MRI-compatible earpiece assembliesare attached to the head coil by their respective first ball joints.

In some embodiments of the apparatus, the first and the secondMRI-compatible earpiece assemblies each include an audio transducerconfigured to deliver audio content to a patient in the head coil.

In some embodiments of the apparatus, at least one of the earpieceassemblies includes one or more RF coils for transmitting RF MRIsignals.

In some embodiments of the apparatus, at least one of the earpieceassemblies includes one or more RF coils for receiving RF MRI signals.

In some embodiments of the apparatus, at least one of the earpieceassemblies includes one or more RF coils for both transmitting andreceiving RF MRI signals.

In some embodiments of the apparatus, the first earpiece assemblyincludes one or more RF coils for both transmitting and receiving RF MRIsignals.

In some embodiments of the apparatus, the first earpiece assemblyincludes one or more RF coils for transmitting RF MRI signals.

In some embodiments of the apparatus, the first earpiece assemblyincludes one or more RF coils for receiving RF MRI signals.

In some embodiments, the present invention provides a method for holdinga patient in a magnetic-resonance imager (MRI) system, the methodcomprising: providing a first MRI-compatible earpiece assembly, thefirst earpiece assembly including a rod connected to a head coil by afirst lockable ball joint and an earpiece connected to a proximal end ofthe rod by a second ball joint; positioning the first MRI-compatibleearpiece to a selected one of a plurality of possible pitch and yawangle combinations of the rod relative to the head coil and to aselected one of a plurality of insertion depths relative to the headcoil; and tightening the first ball joint to yieldably hold the rod atthe selected pitch angle, yaw angle, and insertion depth.

Some embodiments of the method further include providing the head coil,and a second MRI-compatible earpiece assembly, wherein the secondMRI-compatible earpiece assembly is substantially similar to the firstMRI-compatible earpiece assembly but mirror-symmetric to the firstMRI-compatible earpiece assembly about a central plane of the head coil,and attaching the first and the second MRI-compatible earpieceassemblies to the head coil by their respective first ball joints.

Some embodiments of the method further include delivering audio contentto a patient in the head coil through the first and the secondMRI-compatible earpiece assemblies.

Some embodiments of the method further include transmitting RF MRIsignals from the first earpiece assembly.

Some embodiments of the method further include receiving RF MRI signalsfrom the first earpiece assembly.

Some embodiments of the method further include transmitting andreceiving RF MRI signals from the first earpiece assembly.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Although numerous characteristics andadvantages of various embodiments as described herein have been setforth in the foregoing description, together with details of thestructure and function of various embodiments, many other embodimentsand changes to details will be apparent to those of skill in the artupon reviewing the above description. The scope of the invention shouldbe, therefore, determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled. Inthe appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein,” respectively. Moreover, the terms “first,” “second,” and“third,” etc., are used merely as labels, and are not intended to imposenumerical requirements on their objects.

What is claimed is:
 1. An apparatus for imaging a patient in amagnetic-resonance imager (MRI) system, the apparatus comprising: aframe configured to be positioned in a bore of an MRI magnet of the MRIsystem; a first MRI-compatible head-holding assembly, wherein the firsthead-holding assembly includes a first rod slidably connected to theframe by a first lockable frame-held ball joint, and a first cushionedhead-restraining piece connected to a proximal end of the first rod by afirst proximal joint, wherein the first lockable ball joint isconfigured to be loosened and tightened, wherein the first rod ismovably positioned through the first lockable ball joint to a selectedone of a plurality of possible pitch-and-yaw-angle combinations of thefirst rod relative to the frame and to a selected one of a plurality ofinsertion depths relative to the frame, and wherein the first lockableframe-held ball joint is configured to be tightened to yieldably holdthe first rod at the selected pitch angle, yaw angle and insertion depthof the first rod.
 2. The apparatus of claim 1, further comprising: asecond MRI-compatible head-holding assembly, wherein the secondMRI-compatible head-holding assembly includes a second rod slidablyconnected to the frame by a second lockable frame-held ball joint, and asecond cushioned head-restraining piece connected to a proximal end ofthe second rod by a second proximal joint, wherein the second rod ismovably positioned through the second lockable ball joint to a selectedone of a plurality of possible pitch-and-yaw-angle combinations of thesecond rod relative to the frame and to a selected one of a plurality ofinsertion depths relative to the frame, and wherein the second lockableframe-held ball joint is configured to be tightened to yieldably holdthe second rod at the selected pitch angle, yaw angle and insertiondepth of the second rod.
 3. The apparatus of claim 2, wherein the firstand the second cushioned head-restraining pieces each include an audiotransducer configured to deliver audio content to a patient in theapparatus.
 4. The apparatus of claim 2, wherein at least one of thecushioned head-restraining pieces includes one or more RF coils totransmit RF MRI signals.
 5. The apparatus of claim 2, wherein at leastone of the cushioned head-restraining pieces includes one or more RFcoils to receive RF MRI signals.
 6. The apparatus of claim 1, whereinthe first lockable ball joint includes a first threaded rotatable piecethat is rotated to lock the selected one of the plurality of possiblepitch-and-yaw-angle combinations of the first rod relative to the frame,and a second rotatable threaded piece that is rotated to lock theselected one of the plurality of possible insertion depths of the firstrod relative to the frame.
 7. The apparatus of claim 1, wherein thefirst proximal joint is a ball joint.
 8. The apparatus of claim 1,wherein the first cushioned head-restraining piece includes one or moreRF coils for transmitting RF MRI signals.
 9. The apparatus of claim 1,wherein the first cushioned head-restraining piece includes one or moreRF coils for receiving RF MRI signals.
 10. The apparatus of claim 1,wherein the first cushioned head-restraining piece includes one or moreRF coils for both transmitting and receiving RF MRI signals.
 11. Amethod for imaging a patient in a magnetic-resonance imager (MRI)system, the method comprising: providing a frame configured to bepositioned in a bore of an MRI magnet of the MRI system and a firstMRI-compatible head-holding assembly, the first head-holding assemblyincluding a first rod, a first lockable ball joint connected to theframe, and a first cushioned head-restraining piece connected to aproximal end of the first rod by a first proximal joint, wherein thefirst rod is connected to the frame by the first rod passing through thefirst lockable ball joint, and wherein the first lockable ball joint isconfigured to be loosened and tightened; positioning the firstMRI-compatible head-holding assembly to a selected one of a plurality ofpossible pitch-and-yaw-angle combinations of the first rod relative tothe frame and to a selected one of a plurality of insertion depthsrelative to the frame; and tightening the first lockable ball joint toyieldably hold the first rod at the selected pitch angle, yaw angle, andinsertion depth.
 12. The method of claim 11, wherein the frame holds ahead coil, the method further comprising: providing a secondMRI-compatible head-holding assembly, the second head-holding assemblyincluding a second rod, a second lockable ball joint connected to theframe, and a second cushioned head-restraining piece connected to aproximal end of the second rod by a second proximal joint, wherein thesecond rod is connected to the frame by the second rod passing throughthe second lockable ball joint.
 13. The method of claim 12, furthercomprising delivering audio content to a patient in the head coilthrough the first and the second cushioned head-restraining pieces. 14.The method of claim 11, further comprising transmitting and receiving RFMRI signals from the first cushioned head-restraining piece.
 15. Themethod of claim 11, wherein the first lockable ball joint includes afirst threaded rotatable piece that is configured to be rotated to lockthe selected one of the plurality of possible pitch-and-yaw-anglecombinations of the first rod relative to the frame, and a secondrotatable threaded piece that is rotated to lock the selected one of theplurality of possible insertion depths of the first rod relative to theframe, the method further comprising: moving the first cushionedhead-restraining piece to a location against a first side of thepatient's head; rotating the first threaded rotatable piece to yieldablylock the first rod at the selected one of the plurality of possiblepitch-and-yaw-angle combinations; and rotating the second rotatablethreaded piece to yieldably lock the first rod at the selected one ofthe plurality of possible insertion depths.
 16. The method of claim 11,wherein the first lockable ball joint includes a first threadedrotatable piece that is configured to be rotated to lock the selectedone of the plurality of possible pitch-and-yaw-angle combinations of thefirst rod relative to the frame, and a second rotatable threaded piecethat is rotated to lock the selected one of the plurality of possibleinsertion depths of the first rod relative to the frame, the methodfurther comprising: providing a second MRI-compatible head-holdingassembly, the second head-holding assembly including a second rod, asecond lockable ball joint connected to the frame, and a secondcushioned head-restraining piece connected to a proximal end of thesecond rod by a second proximal joint, wherein the second rod isconnected to the frame by the second rod passing through the secondlockable ball joint, wherein the second lockable ball joint includes afirst threaded rotatable piece that is configured to be rotated to locka selected one of a plurality of possible pitch-and-yaw-anglecombinations of the second rod relative to the frame, and a secondrotatable threaded piece that is rotated to lock a selected one of aplurality of possible insertion depths of the second rod relative to theframe; moving the first cushioned head-restraining piece to a locationagainst a first side of the patient's head; rotating the first threadedrotatable piece of the first lockable ball joint to yieldably lock thefirst rod at the selected one of a plurality of possiblepitch-and-yaw-angle combinations of the first rod; rotating the secondrotatable threaded piece of the first lockable ball joint to yieldablylock the first rod at the selected one of a plurality of possibleinsertion depths of the first rod; moving the second cushionedhead-restraining piece to a location against a second side of thepatient's head; rotating the first threaded rotatable piece of thesecond lockable ball joint to yieldably lock the second rod at theselected one of a plurality of possible pitch-and-yaw-angle combinationsof the second rod; and rotating the second rotatable threaded piece ofthe second lockable ball joint to yieldably lock the second rod at theselected one of a plurality of possible insertion depths of the secondrod.
 17. An apparatus for imaging a patient in a magnetic-resonanceimager (MRI) system, the apparatus comprising: a frame configured to bepositioned in a bore of an MRI magnet of the MRI system; and a firstMRI-compatible head-holding assembly, wherein the first head-holdingassembly includes a first positioner connected to a first referenceposition on the frame; a first lockable joint on the first positioner,wherein the first lockable joint is configured to be loosened andtightened; and a first cushioned head-restraining piece connected to aproximal end of the first positioner by a first proximal joint on thefirst positioner, wherein the first cushioned head-restraining piece ismovably positioned to a selected pitch angle and a selected yaw angle ofa plurality of possible pitch-and-yaw-angle combinations of the firstcushioned head-restraining piece relative to the first referenceposition on the frame and to a selected one of a plurality of distancesrelative to the first reference position on the frame, and wherein thefirst lockable joint is configured to be tightened to yieldably hold thefirst cushioned head-restraining piece at the selected pitch angle, theselected yaw angle, and the selected one of the plurality of distances,relative to the first reference position on the frame.
 18. The apparatusof claim 17, wherein the frame includes: a head-coil frame with a headcoil; and a second MRI-compatible head-holding assembly, wherein thesecond head-holding assembly includes a second positioner connected to asecond reference position on the frame; a second lockable joint on thesecond positioner; and a second cushioned head-restraining piececonnected to a proximal end of the second positioner by a secondproximal joint on the second positioner, wherein the second cushionedhead-restraining piece is movably positioned to a selected pitch angleand a selected yaw angle of a plurality of possible pitch-and-yaw-anglecombinations of the cushioned head-restraining piece relative to thesecond reference position on the frame and to a selected one of aplurality of distances relative to the second reference position on theframe, and wherein the second lockable joint is configured to betightened to yieldably hold the second cushioned head-restraining pieceat the selected pitch angle, the selected yaw angle, and the selectedone of the plurality of distances, relative to the second referenceposition on the frame.
 19. The apparatus of claim 18, wherein the firstand the second cushioned head-restraining pieces each include an audiotransducer configured to deliver audio content to a patient in the headcoil.
 20. The apparatus of claim 17, wherein the first cushionedhead-restraining piece includes one or more RF coils that transduce RFMRI signals.